package cn.cai.utils;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
/**
 *普通类调用Spring bean对象：
 *此类需要放到App.java同包或者子包下才能被扫描，否则失效。
 */
@Component
public class SpringUtil implements ApplicationContextAware{
    private static ApplicationContext applicationContext = null;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringUtil.applicationContext = applicationContext;
    }

    public static <T> T getBean(Class<T> type) {
        assertContextInjected();
        return applicationContext.getBean(type);
    }

    //通过name获取 Bean.
    public static Object getBean(String name){
        return applicationContext.getBean(name);
    }
    public static void assertContextInjected() {
        if (applicationContext == null) {
            throw new RuntimeException("applicationContext未注入");
        }
    }
}
